My '94 with the 4-speed GM400 has a whine when I drive off. The note rises with the road speed. I'm not sure if it persists into second gear, as it kind of disappears in the road noise as it gets higher - it's most noticable at about 10-15 mph.

(2018 thread about trans whine: https://www.jaguarforums.com/forum/x...o-89-a-205784/ )

Trans fluid seems good, for whatever that's worth.

I know what I ought to do is try to narrow down the cause during driving. Thing is, I'm just about to take it into the workshop for the long-planned stripdown, and the last thing that happened on the car was a hose cracked and dumped all the coolant on the road. I'm reluctant to spend four hours' worth of cursing and skinned knuckles on replacing hoses and refilling coolant, just so I can go through the cycle of drive-around-then-crawl-under, when I'm just about to hoick the engine and gearbox out onto the bench anyway.

Nonetheless the fact remains - I haven't done a lot on the road to narrow down the issue. It could be the trans, the TC, the diff, the UJs, the crankshaft... in the other thread (link below) it's even suggested that an engine mount could be the cause of low-speed whine!

So I want to try and fix an undiagnosed whine while the car is in the air!

Question 1: Do I have a hope in hell of fixing the undiagnosed whine just by doing normal amateur-grade resto work?

Take it as read that I'll be replacing engine mounts, checking exhaust clearance, doing normal sorting out. Greg's advised me to do the universal joints.

I'm now thinking I might strip and inspect the gearbox as a speculative fix. Might open up the diff too.

Question 2: Exactly how stupid am I? I've never stripped a gearbox before.

3: How much slop should I expect in shafts? Should they be toight or is a little play expected?

4: Any issues with availability of seals and bearings in the UK?

5: Any other advice?

 

Is the whine a new development? Something different than before?

The 400/4l80E transmissions have a rather noisy first gear, period.

People were complaining about it in 1964 when the 400 was introduced and still complaining about it in the 1990s with the 4L80E.

I'd hate to see someone go thru a lot of effort and expense to fix a normal (although annoying) characteristic.

If the noise continues into second gear, though, that's a different matter

Cheers
DD

 

Yep, all mine had noisy 1st gears, some more so than others.

2 were sad in reverse, sometimes, never went looking.

Fresh fluid, OFTEN, shut most up, but I accepted the fact. They be what they be.

 

Yup they all whine in first. I think Jaguar picked the 400/4L80 specifically because it makes Jaguar drivers who grew up with a Moss box in XK's, E Types, and Mark 2's feel right at home.

 

HELL YES.

My MKVII, oh dear, what a song it sand in 1st.

 

Yay if it's normal!

Thanks everyone.

Might strip the blighter anyway. Let's see how close I am to reassembly when it's five months after the planned completion date :-D